This study will examine how disaster related experiences associated with Hurricane Katrina impact changes in substance use and abuse patterns, drug treatment utilization, HIV risk behaviors and networks, and current health status among low income, predominantly African American evacuees living in Houston. Reports indicate that over 150,000 individuals were relocated to Houston from the disaster stricken areas. This research will provide a conceptual framework to explain substance use and abuse, behavioral, and other health related consequences associated with the disaster related experiences of Hurricane Katrina. In addition, this research will provide information on the drug and sexual risk behaviors and risk networks associated with substance use and abuse after natural disasters that can have serious consequences for the spread of Human Immunodeficiency Virus (HIV) and other infectious diseases This application proposes to collect survey data on a sample of 300 drug using Katrina evacuees currently living in the greater Houston metropolitan area 8 months after the disaster. In addition, ethnographic observations and 75 in-depth interviews with a six-month follow-up interview are being proposed to be conducted with a sub-sample. Using the Multivariate Risk Factor Model and a multi-method approach, this study will examine the outcomes of substance use and abuse patterns, drug treatment utilization, sexual and drug HIV and related-infection risk behaviors and risk network characteristics and current health status and will: 1. Provide a detailed examination and the evacuees' disaster related experiences as a result of Hurricane Katrina and the associated psychological distress, other personal trauma and study outcomes; 2. Specify how the relationship between pre-disaster risk factors and current outcomes are mediated by post-disaster risk factors; 3. Specify how the relationship of within-disaster risk factors and current outcomes are mediated by post-disaster risk factors of psychological and other personal trauma, and the effect modification of pre-disaster risk factors. 4. Describe the network characteristics of the relocated drug users' social, drug use and sexual egocentric networks and the extent to which the mixing patterns of these networks; 5. Determine, through the use of ethnographic methods, the extent to which Hurricane Katrina disrupted, stabilized, or influenced in some other manner drug acquisition drug use patterns, and access to and utilization of drug treatment services and the influence of social processes and context. [unreadable] [unreadable] [unreadable]